1. Field of the Invention
The present invention relates to a vehicular lamp and more particularly to a vehicular lamp that has a resin-made plain outer cover.
2. Prior Art
A lamp for a vehicle such as an automobile (merely called a “lamp”) is basically comprised of a lamp body and a lens. The lamp body has a light source, a light reflecting member such as a reflector, an extension element and the like; and its front opening is covered by the lens.
Some of the recent vehicular lamps are configured such that a lamp unit is installed in the lamp body, and the front opening of the lamp body is covered with a plain outer cover. The plain cover is made of a translucent material and has a flat surface and a uniform thickness without any lens steps. In such a lamp, a glass-made plain outer cover is typically used in order to provide a sense of luxury when the lamp is viewed from its front. In other words, a glass-made plain outer cover gives the lamp a sense of luxury because of the color tone of the glass. In addition, when a plain outer cover that has a leg portion formed around its decorative face portion which serves as a front surface region of the plain outer cover is viewed from the front, the leg portion, particularly its thickness, is visually appealing and gives a sense of thickness, and this sense of thickness creates a sense of massiveness for the plain outer cover and provides the lamp with a sense of stateliness and a sense of luxury.
Materials for plain outer covers have been, however, changing in recent years from glass to polycarbonate resin (PC) or the like for the purpose of recycling the lamp and reducing the weight and cost of the lamp. If appropriate resin material is selected, a color tone that is similar to a glass-made plain outer cover is created, and a similar texture as a glass-made plain outer cover is provided for a resin-made plain outer cover.
However, a resin-made plain outer cover has a thinner decorative face portion and a leg surface portion compared to a glass-made plain outer cover. Therefore, the sense of thickness seen in the glass-made outer cover is not obtainable, and it is difficult to provide a lamp with a sense of massiveness and a sense of luxury which a glass-made outer cover can provide. Particularly, when a lamp is viewed from the front, the thickness of the leg portion that exists in a peripheral edge portion of the decorative face portion is generally easily observed through the decorative face portion. Therefore, due to this thin leg portion, the resin-made plain outer cover cannot provide a sufficient sense of thickness and massiveness.
The leg portion of a resin-made plain outer cover can be formed to have the same thickness as that of a glass-made plain outer cover. However, if the thickness of resin increases to the same level as that of a glass-made plain outer cover, a so-called “sink” occurs in the leg portion or the decorative face portion of the outer cover. This deteriorates the appearance of the outer cover, and thus, the lamp cannot have a sense of luxury.
Furthermore, in an ordinary lamp, there is a gap between an extension element installed in the lamp body and the inner surface of the leg portion of the outer cover; and this type of gap is provided also between the peripheral edge of a reflector and the inner surface of the leg portion of the outer cover. These gaps are provided so that the extension element and the reflector do not come into contact with the leg portion of the outer cover. However, such gaps allow the leg portion of the outer cover to be seen through the decorative portion of the outer cover, and the thin leg portion deteriorates the overall appearance of a lamp.
Japanese Patent Application Laid-Open (Kokai) No. 11-306803 and Japanese Utility Model Application Laid Open No. 07-41833, for instance, disclose various lens structures for automobile lamps. The lens in these publications are made of resin, and regions of different thickness or lens steps are formed in the lenses so that lamps can have improved light distribution characteristics and an improved appearance. However, even in these structures, the resin-made lenses do not have such a sense of thickness or a sense of massiveness as that of glass-made lenses.